In an ordinary engine valves are controlled to open and close so that a cylinder may perform an induction and exhaust operation. It is known to use an electromagnetically actuated valve in connection with each cylinder in an internal combustion engine. One such type of electromagnetically actuated valve includes an armature, a pair of electromagnets disposed in opposed relation to each other on opposite sides of the armature so as to be able to apply an electromagnetic attracting force to the armature, and a pair of return springs for biasing the armature toward a neutral position centrally located between the electromagnets.
The electromagnetically actuated valve system of the present invention functions as a replacement for conventional cam driven engine valvetrain systems by substituting electromagnetic actuators and control and power electronics in place of the engine's camshaft, timing gears, timing belt, rocker arm assemblies, and other valvetrain related components. This substitution results in an engine valve actuation system that is fully independent of the crankshaft, thus allowing unrestricted investigation and implementation of various variable valve timing strategies. The benefits of implementing variable valve timing techniques to an internal combustion engine are numerous.
The servo control system of the present invention uses a position-based algorithm to control valve operation. Therefore, the control system looks at the position of the valve armature and determines several factors. First, the system determines whether the valve landing velocity was adequate. Second, the system monitors the position of the armature after it lands. The controller then provides corrections to the power input either for the next cycle, or if a fallout occurs power input is adjusted immediately. Moreover, a feed-forward algorithm allows the control system to predict and provide additional power to correct for sudden changes in engine load. Finally, a self learning algorithm optimizes the feed forward map to minimize the landing velocity and the power consumption under changing load conditions.